论文部分内容阅读
西北地区各板块于古生代末—三叠纪初连为一体,形成了造山带围绕稳定地块的构造格局,为侏罗纪盆地的发生发展奠定了基础。早—中侏罗世时,西北地区整体上处于伸展构造环境,它是南方特提斯洋板块两次俯冲挤压运动之间应力松弛的产物。西北地区的侏罗纪盆地经历了两期盆地类型的发育和叠加,中侏罗世西山窑期结束时的中燕山运动是盆地类型的转型期,早期为伸展型断陷盆地,晚期为挤压型坳陷盆地。根据盆地的力学性质、几何形态、大地构造位置、基底特征和沉积发育特征,可将早—中侏罗世的盆地划分为类克拉通盆地、山间断陷盆地、山前断陷盆地和剪切拉分盆地4种基本类型。中—晚侏罗世挤压环境下的盆地也可相应地分为类克拉通盆地、山间坳陷盆地、山前坳陷盆地、剪切挤压盆地4种基本类型。西北地区侏罗纪原型盆地的形成机制可归结为水平与垂向上两种地壳运动的结合。盆地的演化表现出与造山带和构造带有密切的关系。天山造山带内盆地与两侧盆地的发育主要体现了在岩石圈均衡调整作用下垂向上的互动关系,而阿尔金断裂带的活动方式与侧端盆地的发育则体现了主要由板块构造活动造成的水平运动对盆地的影响。
The plates in the northwestern region were united from the end of the Paleozoic to the beginning of Triassic, forming the tectonic framework of orogenic belts around a stable block and laying a foundation for the occurrence and development of the Jurassic basin. During the early-middle Jurassic, the northwestern region was in an extensional tectonic setting as a whole, and it was the product of stress relaxation between two subduction squeezes in the southern Tethys Ocean plate. The Jurassic basins in Northwest China experienced two types of basin development and superimposition. The Middle Yanshanian movement at the end of the Xishan kiln of the Middle Jurassic was a basin type transitional period, with early extensional faulted basins and late compression Depression basin. According to the mechanical properties, geometry, geotectonic position, basement characteristics and sedimentary development characteristics of the basin, the basins of the Early-Middle Jurassic can be divided into three types: the craton basin, the mountain rift basin, the piedmont faulted basin and the shear Pull the basin 4 kinds of basic types. Middle-Late Jurassic crust can also be divided into four basic types: craton basin, mountain depression basin, piedmont depression basin and shear-squeezed basin. The formation mechanism of the Jurassic prototype basin in the northwest can be attributed to the combination of horizontal and vertical crustal movement. The evolution of the basin shows a close relationship with orogenic belt and tectonic belt. The development of the Tianshan orogenic basin and the two sides of the basin mainly reflects the vertical interaction under the balanced adjustment of the lithosphere. However, the activity patterns of the Altyn Tagh fault zone and the development of the side-trough basin are mainly caused by the tectonic activities of the plate tectonics The impact of horizontal movement on the basin.